1. Field of the Invention
The present invention relates to a sealing structure for providing a seal between panels composing a roof panel to be attached to a roof opening portion of a motor vehicle and, more particularly, to a sealing structure for providing a seal between a sliding panel and its adjacent panels of the roof panel.
2. Description of Related Art
As shown in FIG. 1, a roof panel 10 is mounted to open and close a roof opening portion 12 formed in a roof 14 of a motor vehicle. And conventionally, the roof panel 10 is normally composed of a single panel.
FIG. 2 is a partially cut away cross-section, taken along line A—A of FIG. 1. As shown, a weather strip 16 is attached to a periphery of the roof panel 10 to provide a seal between the roof panel 10 and the roof opening portion 12.
The weather strip 16 includes a base portion 18 to be attached to the roof panel 10, and a tubular portion 20 integrally formed with the base portion 18. The base portion 18 has a trim part having a generally U-shaped cross-section for holding a flange of a frame provided under the roof panel 10, and attaching the weather strip 16 thereto.
When the roof panel 10 is closed, the tubular portion 20 contacts the roof opening portion 12 of the roof 14, and provides a seal between the roof opening portion 12 and the roof panel 10 (Japanese Laid-open Patent Publication No. 2000-335255, pages 3 to 4, and FIG. 1, ex.). The base portion 18 thus arranged, however, has increased dimensions, and accordingly, the weight thereof may undesirably increase.
Furthermore, it has been demanded to enlarge the opening area of the roof 14 for brightening a vehicle compartment, enabling a good airflow, improving a relaxed feeling and obtaining a good view from the vehicle compartment.
Where the roof panel 10 is composed of a single sliding panel, the dimensions and weight thereof increase, and the sliding distance thereof becomes long, thereby enlarging the driving mechanism for the roof panel 10, and deteriorating the designing properties thereof. And when the roof panel 10 is opened, it may project rearward of the vehicle body.
Under the above circumstances, it has been tried to compose the roof panel 10 of a plurality of panels that are arranged in a longitudinal direction of the roof 14. According to this arrangement, sealing is needed between adjacent panels.
As shown in FIG. 3, to provide a seal between adjacent panels, weather strips 22 and 24 are respectively attached to a rear edge of a front-side panel 26 and a front edge of a rear-side panel 28 (Japanese Laid-open Utility model Publication No. Hei 7-35142, pages 6 to 8, FIG. 2, ex.).
To attach the weather strips 22 and 24 to the panels 26 and 28, respectively, it takes much trouble and time, and accordingly, production costs may increase.
In addition, the weather strips 22 and 24 may not always contact each other in a proper condition, because of the variation of the assembling state of the panels 26 and 28, and the deformation of the weather strips 22 and 24 attached to the panels 26 and 28.
On the other hand, weather strips may have a tubular seal portion for improving the sealing properties. When the roof panel 10 is opened, a seal wall of the tubular seal portion may maintain a close contact with a base portion of the weather strip without returning to its original protruded configuration. In addition, the seal wall of the tubular seal portion may generate noise when separating from the base portion of the weather strip. And the compressed tubular seal portion may project outwardly from a space between the panels 26 and 28 to deteriorate the appearance therearound.
The roof panel 10 may be composed of three panels, and rear-side two panels thereof may be made slidable frontward and rearward (Japanese Laid-open Patent Publication No. 2002-356113, pages 2 to 4, FIG. 2, ex.).
In this case, the mechanism for sliding the panels becomes large, and the sealing structure between the sliding panels, and between the sliding panels and the roof opening portion becomes complex. Accordingly, it has been tried to decrease the number of the sliding panels to one, for example.
To provide a seal between the sliding panel and an adjacent non-sliding panel, a weather strip is attached to the sliding panel, or a frame member provided along the roof opening portion 12.
Where the weather strip is attached to the frame member, the tubular seal portion of the weather strip may be pushed by the sliding panel that is slid to its closing position. Consequently, the tubular seal portion may be deformed abnormally and be not located in position between the sliding panel and its adjacent panel, thereby lowering the sealing properties therebetween. And the tubular seal portion may protrude outwardly from a space between the sliding panel and its adjacent panel to deteriorate the appearance around the roof panel, and cause the increase of the air resistance as well as the generation of wind noise.